The present invention relates to a snowmobile drive assembly and more specifically relates to engine and torque converter mounting arrangements for use in a snowmobile.
Heretofore, the most common arrangement of mounting an engine and torque converter on a snowmobile has been to mount the engine on the chassis by vibration isolators, to mount the primary clutch on the output shaft of the engine, to mount the secondary clutch on a shaft rotatably supported on the frame in general parallelism to the output shaft and to interconnect the clutches with a drive belt. The vibration of the engine and its movement as it strains against the vibration isolators during accelerations and decelerations are transferred directly to the primary clutch resulting in unacceptable wear rates in the components of the torque converter and in less than ideal shifting characteristics.
One design offered for overcoming the aforedescribed short comings of the prior art snowmobile drive arrangements is disclosed in U.S. Pat. No. 3,776,354 issued to Duclo et al on Dec. 4, 1973. Specifically, the Duclo et al patent shows the secondary clutch mounted on and adjacent one end of a cross-shaft supported adjacent its one end by a bearing located in a special bracket fixed to the engine, the other end of the cross-shaft being supported in a bearing carried by a chain case bolted to the frame. So that engine vibrations are not delivered to the cross-shaft, a rubber sleeve surrounds the bearing carried by the special bracket. While this patented structure does reduce some of the aforedescribed problems attendant with the prior art designs, the problems are not eliminated since the rubber encased bearing supporting the cross-shaft still permits the latter to move out of parallelism with the output shaft of the engine. Also, for some snowmobile drive arrangements that do not employ a cross-shaft, mounting of the shaft carrying the secondary pulley to a bracket fixed to the engine would be difficult.